1. Field of the Invention
This invention relates to a new and improved spout fitment and a tethered plug-type cap for closing same. More particularly, the invention relates to a fitment which fits around a hole in a panel of a paperboard carton or around a hole in a flexible container, or the like, such as used for packaging liquid products and powders and to a closure for such fitment. The invention is further characterized in that it is tamper-evident. Further, in a modification of the invention, it has container sealing features making it useful in aseptic packaging.
2. Description of Related Art
Generally speaking, prior fitments have spouts with external threads closed by caps with internal threads. Some fitments are used in conjunction with plastic bag containers, the fitment being integrally welded to the plastic bag. Other prior art fitments are attached to a polymer-coated paperboard container such as a gable-top half-gallon container which, optionally, may be lined with foil or plastic. Generally, prior art fitments for paperboard cartons include a thin flange which is welded to the surface of the container. The closure includes a foil seal which seals the mouth of the spout and a liner for the cap which serves a re-sealing function. Attachment to the polymer coated paperboard is accomplished by welding the flange of the spout to the polymer coating. Upon initial removal, the tamper-evident foil seal is removed and discarded.
Fitments of the prior art have a number of deficiencies as compared to the present invention. In the first place, they employ multiple components which increase the cost of the combination very greatly over the simple structures of the present invention. Secondly, the assembly is difficult and involves rotary equipment which is difficult to control in practice and is expensive to install. Thirdly, because of the fact that the prior art spouts are externally threaded, the diameter of the opening in the spout is restricted inasmuch as there is only limited space on the panel of the container on which the flange can be located, thereby reducing the diameter of the fitment flange and correspondingly the internal diameter of the spout. Fourthly, commercially available fitment-closure combinations have no external tamper-evident features, demonstrated, for example, by the internal foil seal of the spout opening of the prior art. Finally, prior fitment-closure combinations have not been adaptable to aseptic packaging.
The openings in prior container panels have been closed off by barrier layers such as shown in U.S. Pat. No. 4,813,578. Such barrier layers are, however, usually part of the laminate of which the container panel is formed. Portions of the plug or cap are secured to the barrier so that when the plug is removed, the barrier is fractured, providing access to the interior of the container. The use of the laminate as the barrier involves manufacturing difficulties which do not occur in accordance with the present invention.
All of the foregoing deficiencies are eliminated in the present invention.
U.S. Pat. No. 3,998,354 discloses an initially one-piece, tethered combination plug and fitment which is stated to be tamper-evident. This reference lacks numerous features of construction of the present invention. It is not disclosed as adaptable to aseptic packaging. It has no tamper-evident feature other than the actual connection between the plug and fitment.